Publication Date:
2017-04-04
Description:
This paper presents an analysis of seismicity
associated with the volcanic activity of Volcàn de Colima
(México) and recorded in the period November 2005–April
2006 during a field survey by the Istituto Nazionale di
Geofisica e Vulcanologia (INGV)–Osservatorio Vesuviano,
the Observatorio Vulcanologico de Colima of Colima
University and the Instituto Andaluz de Geofisica, University of Granada. Three different types of volcanic earthquakes have been identified on the basis of their spectral properties: Type A (0.3–1 Hz), Type B (1–5 Hz) and Type C (3–4 Hz). Results of polarization analysis applied to Type A events show a predominance of radial motion, indicating that the wavefield comprises compressional waves (P) and shear waves polarized in the vertical plane (SV), while the signal always begins with a negative polarity. Type A, B
and C earthquakes have been located using both a flat
layered model and a 3D model including topography.
Hypocentre distributions indicate that the source of Type
A signals is very shallow and confined to a small volume
lying about 1 km below the crater. In contrast, the source of Type B and C events is significantly deeper, with most
hypocentres located in a volume of about 1 km3 centred at 2.5–3 km depth. A cluster analysis based on the crosscorrelation among the waveforms of different events
recorded at the same station was applied to Type A
earthquakes. Only two clusters, which include only a small
percentage of events were found, indicating that earthquake families were uncommon during the period of our survey.
Description:
Published
Description:
887-898
Description:
3.1. Fisica dei terremoti
Description:
JCR Journal
Description:
reserved
Keywords:
Colima Volcano
;
Long Period Events
;
Earthquake location
;
04. Solid Earth::04.06. Seismology::04.06.08. Volcano seismology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
